The present invention generally relates to a power transmission whereby the input speed, from a constant velocity, prime mover, such as an automotive engine, or any other suitable power source, may be reduced to a desired output speed by the internal workings of the transmission.
More specifically the present invention relates to an infinitely variable ratio drive mechanism, of the endless belt type, having a pair of radially adjustable V shaped pulleys configured to rotate on a pair of parallel axes.
An endless, inextensible, belt or chain encircles and drivingly engages both pulleys whereby power may be transmitted from one pulley to the other. A variable speed reduction, between the pulleys, is obtained by selectively moving at least one sheave of each pulley toward or away from the other whereby the effective diameter of the pulleys are controllably varied.
It is well known to use opposing, variable pulleys as the driving member and the driven member in power transmissions as evidenced by the following sampling of U.S. Pat. Nos. 4,433,594; 5,011,461; 6,095,942; 6,135,916; 6,254,503.
In studying variable pulley transmission drive mechanisms it becomes apparent that the variable pulley drive mechanism merely emulates the dual cone variable drive transmission as described in the parent application. Rather than moving the drive belt, or chain, radially along the conical members of the dual cone configuration whereby the operating diameter of the conical members is varied to obtain a desired input to output RPM reduction, the axial distance between the sheaves of the variable pulleys is adjusted thereby emulating the action of the dual cone drive mechanism taught in the parent application.